Development of a simplified methodology for furnace aerodynamics with vortex combustion of organic fuel modeling

This paper describes the process of developing a simplified methodology for furnace aerodynamics during the development or modernization of combustion schemes with direct-flow burners. This technique is based on the use of numerical modeling of air movement and turbulence phenomena in the furnace volume and allows for a relatively short period of time to analyze a large number of options for the burners and nozzles location. This is its advantage in comparison with the use of experimental modeling or numerical simulation with combustion when analyzing a variety of schemes. The model was developed on the basis of validated results of combustion processes numerical simulation in the K-50 boiler furnace. The paper presents the results of calculations performed for several variants of the simplified methodology. For further use, the option that best corresponds to full-scale studies taking into account the fuel combustion process has been selected. The main states of the methodology are formulated.

Hypergolic Ignition of 1,3-Cyclodienes by Fuming Nitric Acid toward the Fast and Spontaneous Formation of Carbon Nanosheets at Ambient Conditions

A hypergolic system is a combination of organic fuel and oxidizer that ignites spontaneously upon contact without any external ignition source. Although their main usage pertains to rocket bipropellants, it is only recently that hypergolics have been established from our group as a revolutionary preparative method for the synthesis of different types of carbon nanostructures depending on the organic fuel-oxidizer pair. In an effort to further enrich this concept, the present work describes new hypergolic pairs based on 1,3-cyclohexadiene and 1,3-cyclooctadiene as the organic fuels and fuming nitric acid as the strong oxidizer. Both carbon-rich compounds (ca. 90% C) share a similar chemical structure with unsaturated cyclopentadiene that is also known to react hypergolically with fuming nitric acid. The particular pairs ignite spontaneously upon contact of the reagents at ambient conditions to produce carbon nanosheets in suitable yields and useful energy in the process. The nanosheets appear amorphous with an average thickness of ca. 2 nm and containing O and N heteroatoms in the carbon matrix. Worth noting, the carbon yield reaches the value of 25% for 1,3-cyclooctadiene, i.e., the highest reported so far from our group in this context. As far as the production of useful energy is concerned, the hot flame produced from ignition can be used for the direct thermal decomposition of ammonium dichromate into Cr2O3 (pigment and catalyst) or the expansion of expandable graphite into foam (absorbent and insulator), thus demonstrating a mini flame-pyrolysis burner at the spot.

Methodological Foundations for Modeling the Processes of Combining Organic Fuel Generation Systems and Photovoltaic Cells into a Single Energy Technology Complex

The needs to reduce the imperfection of theoretical and methodological approaches to value and regulate the processes of applying the methods of transactional energy are substantiated. The concept of combining organizational, economic and mathematical models to improve technical, technological and information methods for the effective integration of renewable and traditional energy facilities has been formulated. This determined the goal of forming a digital platform for machine-to-machine automatic processing of transactions. The creation of the platform contributes to solving a number of research tasks including development of schemes for the use of photo and thermoelements for energy generation in distributed energy and control of electrical and thermodynamic parameters of equipment in sensors of its diagnostics and use in electric drives of actuators of the Industrial Internet of Things. The use of big datа and datа science tools is aimed at achieving a number of practical results. Firstly, the differentiation of the composition of capacities and sources in the complex of hybrid energy facilities has been expanded, secondly, possibilities of modeling has been increased. Furthermore, the results of investigation are the model of integration and balancing regulation in the transactional energy platform of the Center for the Coordination of Interest in Complex Objects.

Carbon Nanostructures Derived through Hypergolic Reaction of Conductive Polymers with Fuming Nitric Acid at Ambient Conditions

Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer. Specifically, the two reagents react rapidly and spontaneously upon contact at ambient conditions to afford carbon nanosheets. Further liquid-phase exfoliation of the nanosheets in dimethylformamide results in dispersed single layers exhibiting strong Tyndall effect. The method can be extended to other conductive polymers, such as polythiophene and polypyrrole, leading to the formation of different type carbon nanostructures (e.g., photolumincent carbon dots). Apart from being a new synthesis pathway towards carbon nanomaterials and a new type of reaction for conductive polymers, the present hypergolic pairs also provide a novel set of rocket bipropellants based on conductive polymers.

Cocatalysts from types, preparation to applications in the field of photocatalysis

With the rapid development of society, the burden of energy and environment is becoming more and more serious, and photocatalytic hydrogen production, photosynthesis of organic fuel and photodegradation of pollutants...

ANALYSIS OF METHODS FOR CAPTURING SULFUR-CONTAINING COMPOUNDS IN FLUE GASES FROM POWER BOILERS

The article discusses the main methods of capturing sulfur oxides in flue gases that are applicable at modern thermal power plants. The main products formed when burning organic fuel at thermal power plants are also considered.As a result of the oxidative reaction, the sulfur in organic fuel is converted into sulfur oxide; sulfur monoxide (SO), sulfur dioxide (SO2), and sulfur trioxide (SO3) are mostly formed. When released into the atmosphere with flue gases, these compounds have a negative impact not only on the elements of the heating unit, but also on the human body, flora and fauna. The conclusions present the main advantages and disadvantages of each method.

Effect of lithium borate coating on the electrochemical properties of LiCoO2 electrode for lithium-ion batteries

The effect of a protective coating of fused lithium borate, Li3BO3, on the physicochemical and electrochemical characteristics of LiCoO2 has been studied. A cathode material produced by the SCS method using binary organic fuel, glycine and citric acid. The influence of the experiment conditions on the morphology, crystal structure and specific surface of lithium cobaltite was studied. Electrochemical testing of LiCoO2∙nLi3BO3 samples, n = 5 and 7 mass %, has been performed in the cathode Li|Li+-electrolyte|LiCoO2∙nLi3BO3 half-cell using 1M LiPF6 in EC/DMC mixture (1:1) as electrolyte in the 2.7-4.3 V range at normalized discharge current С/10, С/5, С/2. The maximal initial discharge capacity of 185 mAh/g was detected for the samples with 5 mass % Li3BO3. The coulomb efficiency of optimal materials in the 40th cycle was 99.1%.